Slide-rule.



G. H. GIBSON.

SLIDE RULE.

APPLICATION FILED OUT. 18,- 1909.

Patented Jan. 3, 1911.

I ll llll l 5 YATTORNEY WITNESSES:

GEORGE i1. GIBSON, or MONTCLAIR, NEW'JERS-EY.

SLIDE-RULE.

Specification of Letters Patent.

Application filed October 18, 1909. Serial No. 523,310.

To all whom it may concern:

it known that I, GEORGE H. GIBSON, a citizen of the United States, residing at Montclair, in the county of Essex and State that with a single setting of the slide thereof a plurality of results may be obtained. This is accomplished by providing a plurality of scales on one member of the rule any one of which may be brought into-coaction with a cooperating scale on the'other member of the rule without occasioning a change in the relative lengthwise positions of the members found when-"setting the instrument for a- I andthe sides 8 of this slot are preferably reading.

In the preferred embodiment of my .in-

vention, the'ruleconsists of a pair of members one ofwhich maybe moved in the di rection of its length relativel to the other and also mayv be rotated wh1le being held agamst movement in the direction of its length; this rotatable member is provided wit aplurality of scales thereon and, by rotating it,a11y oneof these scales may be brought into coaction with the scale on the.

other member. With each scale on the rotatable 'member. and a scale on the other member, a mathematical calculation may performed and the "several scales maybe so id ofl? as to permit of making the calcula-- tions which are most frequentlyfnequired; In this way the instrument may be set .by

me the rotatable member in the direc tion of its length relatively to the other member, and with this one setting of the instrument, 'a plurality of readings may be made, one for each scale'on the-rotatable member which is brought into coaction with;

' "12 are adjustable screws 13 forming pivota scale onthe cooperating member.

The construction which I prefer to employ comprises a stock, a frame. slidable therein,

' ably,-the frame 'fits rather tightly within an opening in the stock, so that when it and the slide which it carries have been positioned lengthwise relatively to the stock, there will be no danger of accidental movement of the slide. Also, means may be prois a section on line 2-2 of Fig. 1', Fig. 3

STATES PATENT orrion.

' Patented Jan. 3, 1911.

is an end view, and Fig. 4 is a perspective view of one end of the rule.

Referring to these drawings, the stock of the rule is indicated at 5, this consisting of a member of rectangular cross-section having a cylindrical bore 6 running lengthwise thereof. At opposite sides of the cylindrical bore are grooves 7 extending lengthwise of the stock. On one or. more sides, the stock is cut to provide a 'slot' extending from the exterior of the stock to the cylindrical bore inclined as shown. A scale ,is applied to each of the faces 8 in the usual or any suitable manner; these faces 8 may als I have grooves 9 cut therein and adapted to receive the lateral edges of a runner 1070f the usual construction including alight metallic frfine and pointersthe-reon or a glass therein, the latter having a straight line drawn thereon. In the drawings, but one slot having scales on its side walls is shown but similar slots may be provided in one'or more of the other. faces of the stock to increase the capacity of the instrument; inthe latter case, I prefer to provide metallic end-pieces or hands 11 at the ends of the stock to firmly unite the parts thereof.

' .The grooves 7 receive the side members of a frame 12 which is adapted to slide' back and forth in these grooves; theside members of the frame fit snugly in the grooves-7 so that the frame will be held by friction ag'ainst unintended movement relatively to the stock. In the end members of the frame pins on which a'cylindrical slide 14'- is re- "t-atably mounted. The slide 14 lies within facilitate rotating the slide relatively to the stock. 'To" one of the end members of the.

frame 12. may be secured a leaf spring 15 the slide in any suitable manner as by marking the scales on thin strips and securing these strips to the surface of the slide.

In using the rule, the frame 12 and the slide carried thereby are moved relatively to the stock with one scale on the slide moving adjacent to one of the scales on the stock; the instrument may thus be set and a reading taken just as is done in using a sliderule of the ordinary construction. During this operation, the slide will be held from rotating by the spring detent 15. The slide having thus been set, it will be held against lengthwise movement relatively to the stock by the friction between the frame 12 and the walls of the grooves 7. The slide may then be rotated to bring another scale thereon into coaction with the scale on the stock and another reading may then be made without having; to reset the instrument. This may be repeated using each of the several scales on the slide. These scales may be such as to permit of making the calculations most voften required, as for 1nstance m using the square, cube, square root, cube root, logar thm, anti-logarithm, sine, tangent, reciprocals, folded-scales, logarithms of logarithms, etc. Thus a number of different mathematical operations may be performed with reference to a single number or amount as a base, the instrument being set only once, since the rotation of the slide to bring different scales onthe slide and stock into coaction may be effected while the slide is held against lengthwise movement relatively to the stock. Another advantage incident to the use of this form of rule is that where a number of mathematical operations are to be performed, each using the result obtained by the preceding one, the intermediate results need not always be read off; thus. not only is time saved, but also the possibility of error in making the reading and in adjusting the slide to correspond there with for the next reading is avoided. Instead of stopping to read the intermediate result, the slide may be rotated to bring up the proper scale for the next operation, and when so rotated it Will'be properly set since longitudinal movement of the slide during its rotation was precluded. Furthermore, by the provision of an inverted scale on the slide, the instrument may always be so used that the result of a first operation will appear on a scale of the stock at a point opposite the zero mark on the coacting scale of the slide, and therefore the succeeding operation will be more readily-performed since, after rotating the slide, the measurement along the scale thereof will be from the zero point. Also, by the use of folded scales, the result of the second operation may be'obtained by rotating the slide but without resetting it longitudinally. It will thus be seen that in many cases a slide-rule constructed as herein described may be used without a second longitudinal setting of the slide for continued operations, this being due to the fact that any scale on the slide may be brought opposite a scale on the stock without losing the longitudinal adjustment of the slide with respect to the stock.

To further extend the usefulness of the rule, the edges of the stock may be marked off as indicated in Fig. 4-to form draftsmens scales. I

Having described my invention what I claim as,new therein and desire to secure by Letters latent of the United States is 1. A slide-rule comprising a stock having a scale,'a frame movable lengthwise relatively thereto, and aslide rotatable in said frame to bring any one of a plurality of scales thereon into coaction with a scale on the stock, substantially as set forth.

2. A slide-rule comprising a stock having .a scale and provided with a lengthwise bore, a lengthwise slot extending into said bore and openings extending parallel to said bore, a frame having parts entering said openings and slidable relatively to the stock,

and a cylindrical slide mounted for rotation in said frame and lying in said bore, said slide having a plurality of scales thereon adapted to coact with -a scale on the stock adjacent to said slot, substantially as set forth.

3. A slide-rule comprising two members which are relatively movable lengthwise thereof and one of which is rotatable, coacting scales 011 said members, and means for checking lengthwise movement of said rotatable member relatively to the other member while permitting rotation thereof, substantially as described.

4. A slide-rule comprising a stock having a scale, a frame movable lengthwise relatively thereto, a slide rotatable in said frame, and a plurality of scales on the slide adapted to be brought into coaction with the scale on the stock, and means for restraining the slide against rotational movement, substantially. 

